Bougainvillea advice

[jsmart]

I got this California gold bougainvillea from a nursery in the beginning of April I repotted it in this pond basket with a bonsai soil mix that I got from the same nursery. The few leaves it had at the time I repotted ended up wilting. I pinched them off and all that was left were the branches. I increased watering to once daily and have been using bougain twice a month. Seems to be doing well (pic below). I’m focusing on letting it grow and thickening the trunk, but looking for any advice or tips with training this for bonsai.
I live in zone 9a, it gets at least 6+ hours of direct sun